There are numerous patent disclosures relating to devices for jiggling fishing lines. For example, the device disclosed in U.S. Pat. No. 2,783,576 employs a clockwork mechanism using a spring motor and escapement to vibrate an arm engaged with the line. U.S. Pat. No. 2,746,198 discloses an electric fish jigger mounted on the fishing rod and employing an electromagnetic vibrator to jiggle a lure on the surface of the water. U.S. Pat. No. 3,600,837 discloses a rod mounted electric motor driving a ratchet wheel to effect jiggling of the line. U.S. Pat. No. 2,908,103 discloses an electric lure jigger wherein a reciprocal motion of the line is obtained by a thermal switch to make and break the electrical connection. More recent disclosures are U.S. Pat. Nos. 3,789,534, 4,420,900, and U.S. Pat. No. 4,528,767, all of which electrically vibrate the line with a reciprocating motion.
Many of the above devices are difficult or expensive to build on a commercial basis and many are different to use and often interfere with paying the line out or reeling it in. Furthermore, while some of the devices of the prior art do jiggle the fishing line when out of the water, it is my experience that they are ineffective in providing significant lure action when in use in the water, presumably due to the damping effect of the water on the line motion.